Refrigeration control apparatus



Jam-6,1942 E,J. DIL'LMANHAL 2,2 9,395

REFRIGERATION CONTROL APPARATUS Filed April 26, 1940 8 INVENTQRS shown).

Patented Jan. 6,1942

UNITED F STATE Sa PATENT o F cE 1.

nllrmcnasrlos CONTROL APPARATUS Earnest J. Diilman, Detroit, and George B. True Grosse Pointe Farms, Mich, assignon to Detroit Lubrlcator Company, Detroit, Mich, a corpora- -tlon of Michigan "applic tion April :6, 1940, Serial s6. 331, p

9 Claims.- (01.132-139) This invention relates generally to control apparatus and more particularly to apparatus for controlling the flow of fuel to the burner of an absorption type refrigerating system. v An object of this invention is to provide an automatic means for regulating the flow of fuel g to an absorption type refrigerating apparatus.

burner seats against an upper seat to prevent leakage along the valve stem.

The invention consists'in the novel apparatus and the improved construction and combination of parts, to be more fully described hereinafter and the. novelty of which will be articularly pointed out and distinctly claimed.

In the accompanying drawing, to be taken as a part of this specification, the preferred embodiment of the invention is fully and clearly i1- lustrated, in which drawing:

the invention: Fig. 2 le s. view in central vertical section in elevation and in a position Just subsequent to the start of a generating period,- and Fig. 3 is a detail view ofthe connection between the valve member and its operating lever.

Referring to the drawing by characters of reference the numeral I designates generally-a control apparatus for controlling flow of a fluid fuel such as gas from a suitable source. of supp y (not The fuel flows tothe apparatus l through ean-ant 2 andtherefrom by means it-an outlet conduit 2 to a burner 4. The

.buffir 4 heats the generator-absorber i to evapcrate and to drive out the absorbed refrigerant contained therein, which maybe ammonia, to-

gether with some entrained absorbent, which I may be water, upward into a bonduit means I which connects thejgenerator-absorber 5 to an evaporator Interposed in th conduit means 8 is a rectifier 8 and condenser 8.- The rectifier I condenses the entrained absorbent so that it can return by gravity flow to the generatorabsorber I. The condenser 9 acts to condense 4 the refrigerant ;driven' from the generator- Figure 1 shows diagrammatically a refrigerating system having a control apparatus embodying 1 the control'apparatus showing the internal parts I spectively,. to bulbs I4, I 5, respectively. The bulbs l4, ii are sensitive to th temperatur of the evaporator I and generator-absorber 5, re- 'spectively. The element It, tube I2 and bulb N form a sealed interconnected system It which contains'a quantity of temperature sensitive vola- I tile fluid and in such a prol n that the entire amount of fluid in liquid phase at any time may be completely contained within either the element Ill or bulb [4. ,The element ll, tube l3 and bulb l5 form a sealed interconnected system II which contains a quantity of temperature sensitive volatile fluid and in such a proportion that the power element llv andtube I3 is unable to accommodate the entire amount of the fluid which is in liquid phase during normal operating temperature conditions.

Fig. 2 shows in greater detail the construction of the control apparatus I which comprises a hollow rectangular casing I8 having substantially parallel side walls I9, 20, a top wall 2|, a bottom wall 22, and a right end wall 23. Cast integral with, and projecting downward from, the bottom wall 22 and adjacent the left end thereof is a holiowboss 23' which has an inlet 24 for conhection with the inlet conduit 2 and an outlet 25- 2 .threaded bosses which extend radially from the side walls of the boss 23' and at right angle to each other. The bosses are preferably vertically I spaced so that the inlet 24 is adjacent the lower -tending' shoulder held tightly to an internal end portion of boss 23" and the outlet is adjacent theupper end portion of boss 23. Spaced substantially midway within the boss 23* between the inlet 24 and the outlet 25 and extending,

transversely to the axis. of the hollow interior of 5 boss 23' is an annular seat member 28 which is I preferably screw-threadedly, secured to the inner wall of the boss 23* and has an -outwardly. ex-

. shoulder 21 of the boss 23. The open lower end absorber I and the condensed liquid'refrlgerant v then flows by gravity to the evaporator I. The

control apparatus l is operated by a pair of pressure sensitive power element it, II which are of the boss 23 is closed to fluid flow by a screwthreaded cap member 28. The annular member 26 has a'raised seat portion 29 adjacent the central hole or passageway therethrough which seat portion 28 cooperateswith a lower seating member 30 of a valve member .II to control flow of fuel through the boss 23* from the inlet 24 to the outlet 25. The bottom wall 22 ha a hollow boss 32 which extends upwardinto the interior of the casing l8 and which opens into and is concentric with the downwardly extending boss 23.-

Screw-threadedly secured within the boss 32 is a to seat member having a seating surface and alongitudinal aperture through which a stem portion 34 of the valve member 3| extends and in which it is guided for reciprocal movement. The

valve member 3| has a second or upper seating member 35 which cooperates with the seating surface of the seat member' 33 to prevent flow of fluid between the valve stem portion 34 and longitudinal aperture of the seat member 33 while the valve member 3| is in its upper position or in a position for allowing flow of fuel to the burner 4. As an additional precaution against the leakage of fuel through the aperture in the seat member 33, there is provided a flexible rubberlike cap member 35 which has a central aperture therethrough; The outer peripheral portion. of

the cap member is held in fluid-tight relation ship to the upper end. of the boss 32 and the inher peripheral portion, surrounding its central aperture, is held in fluid-tight relationship to a recessedportion 31 of the valve stem portion 34 to prevent flow of fluid along the stem portion 34. The lower seating member 35 has a central recess in its upper surface and an upstanding flange at its outer periphery. Positioned adjacent the up- ,per face of member 33 is an annular disk 38 which may be rubber, or any other well known packing-material. The stem portion 34 has, at its lower end-portion, a head which is received within and abuts the lower wall of the recess of th seating member 33. The lower or abutting portion is preferably rounded and the recess is slightly deeper than the thickness of v portion head so that the seating member 35 can have limited movement relative to the valve stem portion 34. The stem portion 34 extends upward through a central aperture in the annular disk 33 and a central aperture in the upper seating member 35. The upper member 35 is held against the disk 33 and rigidly with the lower seat member 30 by inturning the upper edge portion of the seat member peripheral flange.

A shaft or pivot pin has its ends secured in and normalize the plane of the side walls I3, 23 adjacent and substantially parallel to the top wall 2| and adjacent the power element Pivotally mounted on the pin 45 is a lever member 4| having a horizontal plate-like top portion 42 and downwardly extending side portions 43, 44; portion 44 being longer than portion 43 and portion 44 having at its lower end portion an apertured ear or flange 45 and an abutting portion 45'. The lever member 4| is actuated by the powbellows member 53 is sealed in fluid-tight relationship to the inner peripheral portion of the ring member 5| and the other or upper end extends toward the transverse wall 43 andis sealed in fluid-tight relationship to a disk or plate member 54 which is substantially parallel to but is spaced from the wall 45. A thrust member 55, having its upper'end secured to the plate member 54, extends downward through the interior of the stem engages in a recess or indent 55' in the platelike top portion 42 of the lever member 4| intermediate the pin 40 and end wall 23. The casing 41. ring member 5|, bellows member 53 and plate member 54 cooperate to' form a sealed pressure responsive expansible-contractible chamber 55 which is in communication with the tube l3 and forms a part of the sealed system H.

Downward movement of the thrust member 55,

with consequent clockwise rotation of the lever member 4|, is limited by engagement of a screw 51, carried by a side arm 55 of the member 4|, with an inwardly projecting portion 53 of the casing end wall 23. A shaft or pin is carried by the portion 59 and pivoted thereon is a lever member 5| which comprises a horizontal base portion 5| and a pair of vertically extending side flanges 52 (only one of which is shown) havin aligned apertures through which the pin 50 extends. The side flanges have a pair of knifeedge upwardly facing abutments 53 (only one of which is shown). A flange-54 extends outwardly at the lip portion of a cup-shaped member 55 and has a pair of diametrically spaced knife-edge receiving portions 55 (only one of which is shown).

The knife-edges extend into the portions 55 and carry the cup-shaped member 55 with its open side up. A helical coil compression spring 51 has one end located within the member 55 and against the end wall thereof and has its other end extending upward and abutting the underside of the plate-like portion 42. The upper end ofwthe spring 51 surrounds the protuberance of metal made at the time the recess or indent 55 was formed and isthereby located and held in correct position with respect to the member 4|. The spring 51 urges the lever member in a counterclockwise direction and opposes movement thereof by the power element Counterclockwise movement of the lever member 4| is limited by engagement of the abutting portion 45 with a side wall of the projecting portion 53 of the casing end wall 23. The end wall 23 has a boss 53 locatedcentral thereof with a threaded aperture therethrough in which is screw-threaded a shaft member 53.

The shaft member 53 has a rounded end portion extending into the interior of the casing and 1 abutting the edge of the horizontal portion 5| the bellows member 53 and through an aperture in the top wall 2| of the casing The lower end portion which extends into the interior of the casing I is conical in form and the apex thereof of the lever member 5| and longitudinal movement of member 53 acts to pivot the member 5| about the shaft 50. As the shaft member 53 is rotated by means of a suitably calibrated adjustment dial 13 which is held thereto by means of a nut 1|, the rounded end portion is moved longitudinally'to position the lever member 4| thereby 'to adjust the force exerted by the spring 51.

Rotation of the'dial 10 in one direction pivots the lever member 5| in'a clockwise direction to increase the force exerted by the spring 51 so that the pressure within the chamber 55 and consequently the temperature of bulb l5 necessary to rotate the lever member 5| is increased. Rotation of the dial 13 in the opposite direction allows the lever member 5| to pivot in a counterclockwise direction to decrease the force of the spring" and the temperature of the bulb. l3 necessary forrotationv of the lever member 4|. Rotation of the dial" is limited to less than 380 by engagement of a lug 12 of the dial 15 with a protuberance 13 of the casing end wall 23.

A rod or pivot member 15 has its ends secured in and normal to the plane of the side walls l3. 25 about midway between the top wall 2| and bottom wall 22 and substantially parallel to the tially entirely ture-sensitive fluid within the system I3 is fur-- ther preferably proportioned such that the fluid is in a vapor state when the coldest point or the system It is 50 F., or above. The side walls I8 and 20 each has a pair of vertical bosses I22 ex tending fromthe bottom wall 22 to the top wall extends upwardly and into the casing I to prevent rotation of the abutment member I34 when the stud I24 is rotated for adjusting the iorce exerted by the spring I28. A stop member I3I,

' which may be in the form of a slotted washer secured to the upper end portion ofthe stud 2I and which bosses I22 are arranged to form four corners of a rectangle. The open end or the housing I I8 is secured by means of screws to the bosses I22 with the thrust member I20 extending into the casing I substantially centrally of the rectangle formed by the four bosses I22. The thrust member I20 has a cross pin I23 which extends through parallel arms of the lever member I08 on the opposite sides of the rod from the flange I01 so that expansion and contraction of the chamber I2I, caused by changes in pressure due to changes in pressure of the bulb I4, will rotate the member I08 about the rod 15 to I which it is fulcrumed. Increase of temperature of the bulb I4 will cause the thrust member I to move downward into the casing I, thereby rotating the lever member I08 in a counterclockwise direction. counterclockwise movement .of the lever member I88 causes the pawl 85 to engage in the teeth 108 and the pawl 85 and lever member 18 are then moved in a counterclockwise direction until the spring 88 moves overcenter. Subsequent to movement of the spring 88 overcenter, the tailpiece 88 engages the stop face I04, 50 as to lift the pawl or gripping member 88 from the ratchet teeth I08. The bulb element I4 is preferably made of stainless steel, Monel metal, or a similar substance-having a relatively low rate of conduction of heat -so that the temperature of the capillary tube I2 exerts substantially no influence on the temperature oi! the bulb element I4.

I24, serves to prevent rotation of the stud ,l24 sufllcient to move the spring abutment member I21 beyond the upper end portion of the stud I24. Secured to the open end of the housing I I8 and intermediate the bosses I22, there is a plate member I32 having a central aperture I33'throu8h which the thrust member I20 extends. Secured to the plate member I32 within the aperture I33 and extending upward toward the plate member I I8 is an internally threaded tubular element I34. The upper end wall I35 of the element I34 serves as a stop to limit downward or outward movement of the bellows plate member I I8 when the element I 0.is removed from the casing I. An annular, externally threaded nut I38 cooperates with the internal threads of the element I34 to form-a movable abutment. Held under compression within the tubular element I84 and between the plate I I8 and nut I38 is a helical coil spring I31 which surrounds the thrust member I20. The abutment I38 has a slot I38 in its under or outer end I for cooperation with a suitable tool by which the A stud m is journaled within the bottom wall 22 of the casing I and has a portion I25 external of and below the bottom wall 22. The external portion I25 has a slot therein for reception of a 4 suitable tool, such as a screw-driver, for rotation of the stud I24. The bottom wall 22, adjacent the aperture in which the stud I24 is journaled is recessed for reception of an outwardly extend-. ing flange member I28, which may be integral with the stud I24 and prevents downward movement of the stud I24 through the bottom wall 18 as described.

22. The upper portion of the stud I24, extending i into the interior of the casing I, is preferably threaded for screw-threaded reception of adjustable spring abutment member I21: The upper end race of the stud I24, upon engagement therewith by the member I20, serves as a stop to limit the expansive movement of This engagement/by the member I20 preferably occurs when the coldest point or the system is approximately It. or the temperature at which the temperature sensitive fluid is substanin a vapor state.

A helical coil spring I28 is concentric with the thrust member. I20 and stud I24 and is held under compression between a spring abutment member I28, secured to the thrustmember I20 and the adjustable spring abutment member I21 threaded on the stud I24.- Preferably the circumferential portion of the member I21- has a recess or aperture thereth'rough'which cooperates with a vertically extending pin I38 secured to the bottom wall 22 or the casing I. and which the chamber I2I.

abutment I38 may be rotated to adjust the force exerted by the spring I31. v

Extending downward in a slot I38 on the innersurface of the wall 20' is a hand reset pull rod or starting member I40. The pull rod I40 is arranged for reciprocal movement in the slot I38 and has an intumed lip portion I which extends from the wall member 20 into the casing I and is operable to engage the underside of the plate-like arm 11 of the member 18. Upon up-- ward movement of the rod I40 to rotate the member' 18 into operative engagement with the stop face I04, the valve member II is moved into position whereby fluid can flow from the inlet conduit 2 to the outlet 3'to start a heating cycle of operation. The rod I40 has an offset portion I 42 external of the casing I which serves as a convenient means for grasping therod I40 so that it may be moved upwards to rotate the member The casing I is closed at its left end By means ofa cover member; I43 which has its lower end held as by means or a screw against a boss I44 projecting upward from the bottom wall 22. The top portion of the cover member I43 is received beneath a portion of the power element I0.

The operation of the control apparatus is as follows: Upon installation or the apparatus, the

temperature of the generator-absorber bulb element II and otthe 8 will be low relative to its generating operating temperature so that the engaging portion of the lever member M will be in engagement with the portion 88. The bulb element I4,which is in'thermal relationship with the evaporator 1, and sensitive to the temperature of the refrigerant therein. will be warm relative to the evaporating temperature of the evaporator and the pressure within the system I8 will be high so that the chamber I2I will have expanded and the thrust rod I28 will be in engagement with the upper surface of the stud I24. If the valve member 3| is in itaupper position,asshownin Fig.2,thenitis merely'to turn on the gas supply at the source and to light the burner 4 inorder to put the retrlger ating system into operation. However, it the car 80, said flanges and ear having aligned apertures receiving the rod 15. The arm 11 extends toward the end wall 23. A d'owntumed leg 8| extends from the member 16 below the rod 15. Projecting into the aperture in the arm 11 and extending substantially toward the rod 15 from the right hand cross member (facing Fig. 2), is a pointed or V-shaped projection 82 which serves as a point abutment for a snap-acting means to be described in detail hereinafter. A lip or ear 83 is bent upward from the arm 11 at the front inside edge of the aperture thereof. The ear 83 and the front side flange 18 have aligned apertures'which receive the ends of a supporting pin 84. The-pin 03 carries for pivotal movement a pawl or grippingmember 85 having a tail piece 86. The front flange 18 has projecting upward therefrom, intermediate the pin 84 and the rod 15, a stop member 81 having an upwardly inclined edge, the purpose of which will be brought out hereinafter.

position may be accurately adjusted. This adjustment, after having once been made, should remain fixed and therefore the member 95 is soldered or otherwise bound to the stem portion 34 subsequent to adjustment. Rotational movement of the lever member 16 is limited by a stop member I02 which has a pair of vertically faced shouldersor stop faces I03 and I04 engageable with-the free end of arm 11. The member I02 is secured by a screw to-a boss or projecting portion I05 rigid with, and extending upward from, the bottom wall member 22 within the casing I. The plate-like arm 11 engages the stop face I03 to limit clockwise rotation of the lever member Upon counterclockwise rotation of the lever member 16, the tail piece 86 of the pawl 85 engages the face I04 thereby rotating the pawl 85,

' and upon continued counterclockwise rotation of The levers 4 I, 16 are operatively connected by a' thrust member or flat rod 88 which has a longituthe rod 88 when under a compression force. One end portionof the rod 88 is preferably slotted at its side edges to form a T-end portion which interlocks with a slot in the leg 8| so 'that the rod98 is pivotally connected to the lever member 16. The other end portion 90 of the rod 88 is of reduced width and has a shoulder 9I which is formed at the intersection of the reduced width portion 90 with the normal width portion. The portion 90 extends within the aperture in the ear 45 and the shoulder 9| is engageable by the ear 45 for movement of the rod 88 in one direction. Pivoted on the rod is a channelshaped valve carrying lever or actuating valve member 92 having a pointed or sharpened end portion 93 facing the V-shaped portion 82 of the lever member 16 and having at its other 'end a rounded lip portion 94 which extends at right angles to the longitudinal axis of the lever member 92 and which substantially overlies the valve member 3 I. A collar .member 95 having an intermediate portion'96 embraced by the lower and upper spaced, polygonal flanges or abutments 91,

98, receives the portion 94. The member 95 is adjustably screw-threaded on'a valve stem portion 34 which projects upward into the casing I through the upper seat member '33.

The lever member 92 is connected to lever member 16 by a helical coil spring 99 held under compression intermediate 9. pair of springabutment members I00, IOI which have theirrecesses in point contact with the portions 82 and 93 respectively. The spring 99 serves as a snap- I acting means for moving the valve member 3I with a quick movement into cooperative relationship with .eithr of the seat members or 33 andpsnpplie's the necessary force to insure a tight the member 16, pawl 85 is rotated clockwise until the tail piece 86 engages the arm 11 thereby limiting upward movement of the lever member 16.

A lever member I08 is pivoted on the rod 15 between the intermediate flange 80 and the rear side flange 19, and has a vertical flangeor portion I01 extending toward and cooperable with the pawl 85. The flange I01 has an arcuate edge with an intermediate grippingsurface comprising upwardly inclined ratchet teeth I08 for cooperation with the downturned or hooked end of the pawl 85. Above and below the teeth.I08 there are upper and lower smooth surface portions I09, IIO, respectively, cooperable with and on which the pawl 85 can rest. The member I06 has a releasing member or lip III cooperable with a.

.holding member, as hereinafter described, to

' I01. Also pivoted on the rod 15, intermediate the' seat member 33 and open the inlet conduit 2' to flow of fluid to the outletconduit' 3.

seating engagement. The spring 99 also prevents the valve member ill from attaining an intermediate position in which the fuel flowthroughthe burner 4 is insuflicient to maintain proper combustion. The threaded connection between over center to snap the valve member to each the stem portion34 and the collar member as I cause the pawl to engage the vertical flange ear8'0 and the front flange 19, is a stop finger or holdin member II2 having a free end portion II3 normally held in engagement with the stop member 81 of the lever member 16 by a h'elical coil tension spring H4. The spring II4 has one end portion held in an. apertured ear on the finger H2 and its other end portionsecured in an apertured ear onthe pawl or detent 85. The finger H2 is engageable with the detent85 below a shoulder I I5 to hold-the detent 85 out of en-' gagement with the ratchet teeth I08 under certain conditions of operation: Upon pivotal movement .of.:-the'finger I I2 by the lip III, the free end portion H3 is raised above the shoulder H5 to release the detent 85. so that it can rotate counterclockwise and into engagement with the circumferential edge of the flange I01. Engagement of the detent 85 and the teeth I08 of the member I06 connects the lever member I06 to the lever member 16 so that upon counterclockwise rotation of the lever member I06, the lever member 16 will be rotated counterclockwise to rock the spring 99 overcenter thereby to cause the valve. member 3| to be moved into engagement with the The power element I0 is'of the usual type and comprises a metallic bellows element H6 sealed atone end to .an annular member In which is sealed to the inside of and adjacent the open end of a cup-shaped housing .I I8. The bellows element II6 has its otherorinner end sealedeby a plate member I I9 which carries a movable thrust member I20. The housing member H9, annular member II1, element IIB'andplate member; I I9 form a pressure sensitive, expansible-contractible chamber I2I which is in open communication by 2,269,395 valve member 8| is-in its lower position with the seating surface 80 against the seat portion 28, it will be necessary to lift the starting member or pull rod I40 by manually gripping the portion I42 and pulling it upward. Upward movement of the rod I40 causes the lip portion I to engage the underside of the plate-like lever member I8 andv lift it upward, thereby moving the helical coil spring 88 overcenter so that the lever member 82 is pivoted clockwise and the valve member 3| is moved to open position. Upward movement of the lever member I8 is limited by engagement of the'tail piece 88 with the face I04, and of the tail piece with. the surface of the plate-like lever member I8. In this position, the

pawl or detent 85 will be held, as shown, out of engagement with the circumferential edge of the flange I01, and out of engagement with the free end portion II3 of the holding member II2.

As the temperature of the generator-absorber 5 increases, the temperature of the'bulb I5 will increase, thereby increasing the fluid pressure termined temperature, the pressure within the, I system I! will have increased sufliciently so that the chamber 58 will expand, forcing the thrust member 55 downward to rotate the lever member III in a clockwise direction. Clockwise movement of the lever member 4| causes the flange 45 to engage shoulder SI of the thrust rod 88 and to move the thrust rod toward the left. Movement of the thrust rod 88 toward the left acts through the downturned leg 8I to rotate the lever member I8 in a clockwise direction. After the lever member I8 has moved in its clockwise direction sufficiently, the V-shapedportion 82 will have moved past a line of centers drawn through 'rod I5 and the sharpened end portion 88 thereby to move-the spring 98 overcenter so that the spring will act to rotate the lever member 82 in a counterclockwise direction. Counterclockwise movement of the lever member 82 acts to move the valve member ill to its down position, thereby stopping the flow of fuel to th burner 4. Movement of the lever member I8 in a clockwise direction is limited by engagement thereof .with the surface I03. Itis necessary only that the lever member H be rotated clockwise by the power element sufficiently to cause portion 82 to pass. beyond the said line of centers drawn from the center of the rod I5 through the point 93, because continued movement of the lever member I8, irrespective of lever member 4|, will be caused by the expansive force of the spring 88, and this is possible because-of the lost motion between the-thrust member 88 and the flange 45. To prevent undue strain from beingexerted by the power element through the lever member 4I'to the thrust rod 88, the stop member or screw 51 is adjusted so that itengages-the top face of the wall portion 58 Just subsequent to movement of the point 82 through said lineof centers drawn through rod I8 and portion 88 so that the spring .88 will cause continued movement of the lever member I8.

- The thrust rod I20 was already in its downward position engaging the top face of the stud I24 and-the flange M1 in its extreme counterand holding the finger- II2 ina' raised position.

Upon release of the tail piece 88 from the stop face I 08 and due to the force of the spring II 4, the detent or pawl 85 will be. rotated counterclockwise. The finger H2 is in its raised position as stated so that the free end portion II8 thereof passes above the. shoulder II of the pawl 85 and the detent engages the surface portion IIO of the lever member portion I0I.

After the flow of gas to the burner 4 has been stopped, the generator-absorber 5 begins to cool toward room temperature. Cooling of the generator-absorber 5 causes evaporation of the condensed refrigerant in the evaporator I and consequent cooling thereof and of the bulb I4. As

the bulb I4 cools, the pressure within the sys--,

- tem I8 decreases, with consequent contraction of the chamber 'I2I. I2I allows spring I28 to thrust the member I 20 upward and rotate the lever member I08 clockwise, and the pawl will slide over the remainderofthe surface portion H0 and the teeth I08 to the surface portion I08, at which time the tem.-.- perature of the evaporator I will have been brought down to suitable refrigerating temperature. As the refrigerant evaporates in the evaporator I and the quantity therein decreases, the temperature of the evaporator will increase causing an increase in the temperature of the bulb Continued increase in the evaporator tern perature to 27 F. causes the firsttooth of the teeth I08 tov engage the pawl 85 and to move the lever member I08 and the lever member I8 in acounterclockwise direction and into the position shown in Fig. 2. Itwill be noted that after the pawl 85 hasrotated the lever member I8 suiiiciently'in a counterclockwise direction the spring 88 will pass overcenter, and the lever member I8 will be rotated thereby until the tail piece 88 V engages the stop face I04 at which time the pawl 85 will be rotated clockwise about the pin 84 .andlift the pawlv 85 from the teeth I08. The

valve member 8| will then be opened to allow flow of' fuel to the burner 4 and the pawl '85'will be held by the stop-face I 04 out of engagement with the lever member I08.

It is possible that the first evaporating period of the evaporator I will not be sufliciently long to lower the temperature thereof to 18 F. andif such is the case, the gripping portion of pawl 85 will not slide to the smooth surface portion I08 but will remain'somewhere on the teeth I08. If

such is the case, as soon as the temperature of the evaporator begins to rise sufficiently and the temperature of the bulb I4 increases substantially, say 9 F. to 12 F., the lever member I08 will be rotated counterclockwise and the pawl 85 which is gripped to the teeth I08 will rotate the lever member I8 for movement of the valve member 8| to fuel supplying position as described. If the evaporator temperature always went below 18 F. there would be no need for more than one n tooth on the flange I01, but, as has just been set forth, such may not always be the case at starting of the refrigerating apparatus and such might not be the case should warm water or desserts be put into the evaporator for freezing clockwise position so that the lip III is engaging 85 during a generating period ofth'e system.

This contraction of chambermaximum operating temperature and counter- 6 clockwise rotation of the dial I decreases the same. v

Subsequent refrigerating cycles are substantiallyas described, with the power element It acting at a bulb l4 temperature of about 27 F. 161

, secured to said casing, means including a snap to start the flow of gas to the burner 4, and the power element H acting at a maximum bulb I! temperature of from 260 F. to 380 F., depending upon the setting of dial 10, to stop the flow of fuel to the burner 4.

It may sometimes happen that the temperature of the bulb i5 will reach the maximum temperature at which it stops flow of gas to the burni er'4 prior to the movement of the thrust member I into engagement with the top surface of the :0

stud I24. Under such operation the pawl, unless prevented, might drop into the toothed portion I08 and the lever member 16 be moved again into gas supplying position before an evaporating period takes place. This is-prevented by engagea ment of the shoulder H5 with the end surface H3 of finger H2. Such operation is entirely abnormal and will'seldom o'ccur.

Should the ambient temperature surrounding the element Ill decrease substantially below 50 '30 F. sufficient pressure within chamber l2l to cause the thrust member I20 to engage the top surface of stud I24 may not occur. This means that the lever member I06 will not be rotated sufficiently in a counterclockwise direction to raise, by en- 'gagement of the lip Hi with the finger H2, the end surface H3 so that it will extend above the shoulder H5. 'I'herefore'the finger I I2 will hold the pawl 85 from engaging the portion I01 and as soon as the next evaporating cycle portion is 0 completed the refrigerating apparatus is automatically shut down until it is started by manual operation of rod 0.

It may now be seen that this invention provides ameans which is simple of manufacture and operation for controlling the operation of a cycling absorption type refrigerating system in a most satisfactory manner and one which upon the occurrence of a, low ambient temperature will automatically stop operation thereby to prevent freeze up of the space cooled by the refrigerating apparatus.

What is claimed and is desired to be secured by Letters Patent of the United States is:

1. In an apparatus of the character described,

a casing having a wall, controlling means having .an operating member, "an actuating element secured rto said casing, means including a snap acting mechanism interconnecting said actuating element and said operating member for op do eration of said controlling means by said actuating element with a quick movement, a second actuating element secured to said casing adjacent said wall, a first lever means fulcrumed on said casing and operatively connected to and operable to be moved by said second actuating element and having an extending portion, force transmittin means interconnecting said lever means and said snap acting mechanism for movement thereof thereby to actuate said controlling ,means; an IQ abutment carried by said wall, abutment means carried by said lever means extending portion and engageable with said abutment to limit movement of saidlever means in one direction,

force exerted by said stressed means.

2.In an apparatus of the character described, a casing having a wall, controlling means having an operating member, an actuating element acting mechanism interconnecting said actuating element and said operating member foroperation of said controlling means by said actuating ele- 1 ,ment with a quick movement, a second actuating element secured to said casing adjacent said wall, a first lever means fulcrumed on said casing and operatively connected to and operable to be moved by said second actuating element and having a finger portion, force transmitting means interconnecting said lever means and said snap acting mechanism for movement thereof thereby to actuate said controlling means, an

abutment carried by said wall, abutment means carried by said lever means portion and engage able with said abutment to limit movement of said lever means in one direction, a fulcrum member carried by said casing, a second lever means fulcrumed on said fulcrum member, means under stress between said first and said second lever means and acting to move said first lever means in a second direction, thrust means carried by and extending through said wall and having one end portion within said casing and engageable with said second lever member, said thrust means having a second end portion external of said casing, and manually operable means cooperable with said second end portion and operable to be manually operated for moving said second le er means and adjusting the force exerted by said stressed means.

3. In an apparatus of the character described, a casing having a wall, controlling means having an operating member, an actuating element secured to said casing, means including a snap acting mechanism interconnecting said actuating thereby to actuate said controlling means, an

abutment carried by said wall, adjustable abut-- ment means carried by said lever means portion and engageable with said abutment to limit movement ofsaid lever'means in one direction, a fulcrum member carried by said wall, a second lever means fulcrumed on said fulcrum member and having a portion underlying said first lever means, a spring abutment member having a portion positioned against said second lever means portion, a helical coil spring under compression between said first lever means and said spring abutment member and acting to move said first lever means in a second direction, means on said first lever means forpositioning one'end of said spring, the other 'end of said spring being posh" tioned by said spring abutment member, thrust means threadedly secured to and extending 'a fulcrum member carried by said casing, a sec- 5 through said w l and having one end portion within said casing and engageable with said second lever member, said thrust means having a second end portion external of v said casing, and manually operable means secured to said second end portion and operable to be manually rotated for rotation of said thrust means for moving said second lever means and adjusting ,the

force exerted by said spring.

4; In an apparatus of the character described,

a casing having a wall and having a passageway 10 therethrough including a valve port, a valve controlling ,fiow through said passageway and hav-' ing an operatingmember, an actuating element secured to said casing, means including a snap acting mechanism interconnectingsaid actuating element, and said operating member for operation of said valve by said actuating element with a quick movement a second actuating element secured to said casing adjacent said wall, aflrst lever means fulcrumed on said casing and operatively connected to and operable to be moved by said second actuating element and having a finger portion, force transmitting means interconnecting said lever means and said snap acting mechanism for movement thereof thereby to actuate said valve, an abutment carried by said wall, adjustable abutment means carried by said lever means portion and engageable with said abutment to limit movement of said lever means in one direction, a fulcrum member carried by'go said wall, a second lever means fulcrumedon said fulcrum member and having a portion underly I ing said first lever means, a spring abutment member having a portion positioned against said second lever means portion, a helical coil spring 5 under compression between said first lever means and said spring abutment member and acting to move said first lever means in a second direc-.

tion, means on said first lever means for positioning one end of said spring, the other end of 40 said spring being positioned by said spring abutment member, thrust means threadedly secured to and extending through said wall and havin one end portion within said casing and engageable with said second lever member, said thrust means having a second end portion external of said casing, manually operable means-secured to said second end portion and operable to be manually operated for screw-threading said .thrust means thereby to move said second lever means 0.

and adjust the force exerted by said spring, stop means carriedby the external surface of said wall, and means on said manually operable -means and cooperable with said stop means to limit movement of said manually operable means.

5. In an apparatus of the character described, a casing having a wall and having a passageway therethrough including a valveport, a valve controlling flow through said passageway and having an operating member, an actuating element secured tosaid casing, means interconnecting said actuating element and said operating member for operation of said valve by said actuating element, a second actuating element secured to said casing adjacent said wall, a first lever means ful- I 85 crumed on said casing and operatively connected to and operable .to be moved by said second actuating element and having a finger portion, force transmitting means interconnecting said lever means and said interconnecting means for movement thereof. thereby to actuate said valve, an abutment carried by said wall, adjustable abutment means carried by said finger portion and engageable with said abutment to limit movem nt of said lever means in one direction, a 76 fulcrum member carried by said wall, a second lever means fulcrumed on said fulcrum member and having a pair o'f spaced knife edge portions underlying said first lever means, a cup-shaped member having an outtumed lip at its open edge portion, saidlip having knife edge receiving portions' for receiving said second lever means portions, a helical coil spring under compression between said first lever means and said cup-shaped member'andacting to move said first lever means in a second direction, means on said first lever means for positioning one end of said spring, the other end of said spring being positioned bythe side walls of, said cup-shaped member, thrust means threadedly secured to and extending through said wall, and having one end portion within said casing and engageable with said second lever member, said thrust means having a second end portion external of said casing,

manually operable means secured to said second end portion and operable to be manually operated for screw-threading said thrust means thereby to move said second lever means and adjust the force exerted by said spring, stop means carried by the external surface of saidwall, and means on said manually operable means and cooperable with said stop means to limit movement of said manually operable means;

6. In an apparatus ofthe character described,

a casing having a wall and having a passageelement with a quick movement, a second actuating element secured to said casing adjacent said 'wall, a first lever means fulcrumed on said casing and operatively' connected to and operable to be moved by said second actuating element, force transmitting means interconnecting said lever means and said snap acting mechanism for movement thereof thereby to actuate said valve, lost motion means interconnecting said force transmitting means and said lever means thereby to l allow movement of said lever means in one direction without movement of said force trans-, mitting means, an abutment carried by said wall and having a plurality-of spaced surfaces, said lever means having an engaging portion for en-- gagement with one of said spaced surfaces for limiting movement of said lever means in one direction'and having a portion overlying another of said spaced surfaces, adjustable abutment means carried by'said overlying portion and engageablewith said other surface to limit movement of said lever means in a second direction, a

fulcrum member carried by said wall, a second lever means fulcrumed on said fulcrum member and having a pairof spaced knife edge portions underlying said first lever means, a cup-shaped member having an outtumed lip at its open edge portion, said lip having-knife edge receiving portions for receiving said second lever means portions, a helical coil spring unde'r compression be-" tween said first lever means and said cup-shaped member and acting to move said first lever means in said one direction, means on said first lever means forpositioning one end-of said spring, the

other endof said spring being positioned bythe side walls of said cup-shaped member, thrust means threadedly secured to and extending through said walland having one end portion within said casing and engageable with said second lever member, said thrust means having a second end portion external of said casing, manually operable means secured to said second end portion and operable to be manually operated for screw-threading sa' 1 thrust means thereby to move said second lever means and adjust the force exerted by said spring, stop means carried by the external surface of said wall, and means on said manually operable means and cooperable with said stop means to limit movement of said manually operable means.

'7. In a control device, a supporting casing, a plurality of downwardly directed power exerting elements mounted in lateral relation on said casing, substantially parallel thrust members extending toward the bottom wall of said casing and operable one by each of said elements, an overcenter lever mechanism comprising an actuating lever and a main' lever having a transverse arm, a spring interposed between said levers and operable on movement of said main lever to move said actuating lever, clutch mechanism operable to connect one of said thrust members to said main lever, a lever member in opposed relation to said arm and having an end portion engage able by the other of said thrust members, a link loosely supported by said lever member and positioned between and for transmitting the thrust of said lever member to said arm, and a control means carried by said casing and operable by said actuating lever.

said actuating lever, clutch mechanism operable to connect one of said thrust-members to said main lever, means to release said clutch mechanism upon operation of said main lever by said one thrust member, a lever member in opposed relation to said arm and having an end portion engageable by the other of said thrust members. a link loosely supported by said lever member and ating lever and a main lever having a transverse arm, a spring interposed between said levers and operable on movement of said main lever to move said actuating lever, clutch mechanism operable to connect one oi said thrust members to said main lever, a lever member in opposed relation to said'arm and havingan end portion engageable by the other of said thrust members, a link loosely supported by said lever member and positioned between and for transmitting the thrust of said lever member to said arm, an abutment on said supporting casing and engageable by said. lever member to limit the thrust of said lever member upon said link, a pressure determining spring acting through said lever member to oppose said other thrust member, means engageable by and limiting the movement of said lever member by said pressure determining spring, and a control-means carried by said cas ing and operable by said actuating lever.

EARNEST J. DILLMAN. GEORGE R. TRUE. 

